This invention relates generally to in-vehicle navigation systems and more particularly to vehicles as are also equipped with roadside information radio reception services.
In-vehicle navigation systems are known in the art. Such systems often function to present an in-transit set of instructions to guide a driver of a vehicle to a previously identified journey goal. Such systems often use the global positioning system and/or other in-vehicle location determining mechanisms (such as automatic dead-reckoning sensors and tools) to ascertain a present location of the vehicle. This information is utilized in combination with previously stored map information to identify a viable path by which the vehicle can reach the identified destination. Driving instructions are provided to the driver in a variety of ways, including by graphic display of a map, display of textual instructions (sometimes in combination with instructional symbology such as directional arrows), and/or audio cues.
Wireless communications are also known in the art. Wireless systems making use of frequency reuse, such as cellular systems, are virtually ubiquitous and dispatch services are also well integrated and dispersed. Both are key components of modern infrastructure.
Now, at least one group seeks to define a new wireless communications service to specifically facilitate terrestrial-based vehicular journeys (particularly for automobiles and trucks). Presently known as dedicated short range communications (DSRC), the Federal Communications Commission in the United States has presently at least tentatively identified spectrum that can be used for such journey-related information. The American Society for Testing and Materials presently acts as a standards development group to define such a communications service to support provision of journey-related information to vehicular users. At present, the over-the-air interface has not been defined (though at least two wireless local area network systemsxe2x80x94the I.E.E.E.#802.11a and Motorola""s control channel based Freespace systemxe2x80x94are enabling, have been proposed, and are being considered). This group has, however, made considerable progress towards defining the services that the service will support. In particular, such a journey-related information provision system should ultimately provide roadside information and corresponding vehicle-to-vehicle communications to support both public safety and private requirements (depending upon the application, transmission range will likely vary from fifteen meters to three hundred meters).
As an example of public safety services, such a roadside information system can be expected to support:
Traffic count (for example, determining the number of vehicles that traverse an intersection over a given period of time);
Traffic movement information;
Toll collection;
In-vehicle signage (for example, presenting xe2x80x9cstopxe2x80x9d information within the cockpit of a vehicle as the vehicle approaches a stop sign);
Road condition warnings;
Intersection collision avoidance (including highway/rail intersections);
Vehicle-to-vehicle information (for example, stopped vehicle or slowing vehicle information);
Rollover warnings;
Low bridge warnings;
Border clearance facilitation;
On-board safety data transfer;
Driver""s daily log;
Vehicle safety inspection information; and
Emergency vehicle traffic signal preemption.
Examples of private requirements include:
Premises access control;
Gasoline payment;
Drive-through retail payment;
Parking lot payments;
Various vehicular related data transfers (for example, diagnostic data, repair service record data, vehicular computer program updates, map information, and user content such as music);
Rental car processing;
Fleet management;
Locomotive fuel monitoring; and
Locomotive data transfer.
When a vehicle has both a navigation system and a roadside information service-based system, a likelihood exists that information provided by these two systems will, from time to time, conflict. Such conflicting information can, at a minimum, distract or confuse a driver. A need therefore exists for a way to at least minimize confusing or misdirecting a driver through provision of conflicting information from such systems.